Listen to your vet. It is quite common for German Shepherds to refuse to eat enough to completely hide their ribs. Accept it, she will live longer than overfed dogs. Read through
https://www.askmehelpdesk.com/dogs/b...ghlight=Saluki
If she hasn't been spayed, she may use up less nervous energy if you do so.
I want to thank you for rescuing her. There are so many great dogs out there needing homes. Please come back if you need any other help.
Added note. I asked to have this move to dogs. That is part of the purpose of the Report inappropriate post link at the top of every thread.